Wireless networks are ubiquitous and are commonplace indoors and becoming more frequently installed outdoors. Wireless networks transmit and receive information utilizing varying techniques. For example, but not by way of limitation, two common and widely adopted techniques used for communication are those that adhere to the Institute for Electronic and Electrical Engineers (IEEE) 802.11 standards such as the 802.11n standard and the IEEE 802.11ac standard.
The 802.11 standard specifies a common Medium Access Control (MAC) Layer which provides a variety of functions that support the operation of 802.11-based wireless LANs (WLANs). The MAC Layer manages and maintains communications between 802.11 stations (such as between radio network cards (NIC) in a PC or other wireless devices or stations (STA) and access points (APs)) by coordinating access to a shared radio channel and utilizing protocols that enhance communications over a wireless medium.
802.11n was introduced in 2009 and improved the maximum single-channel data rate from 54 Mbps of 802.11g to over 100 Mbps. 802.11n also introduced MIMO (multiple input/multiple output or spatial streaming), where, according to the standard, up to 4 separate physical transmit and receive antennas carry independent data that is aggregated in a modulation/demodulation process in the transceiver. (Also known as SU-MIMO (single-user multiple input/multiple output.))
The IEEE 802.11ac specification operates in the 5 GHz band and adds channel bandwidths of 80 MHz and 160 MHz with both contiguous and non-contiguous 160 MHz channels for flexible channel assignment. 802.11ac also adds higher order modulation in the form of 256 quadrature amplitude modulation (QAM), providing a 33-percent improvement in throughput over 802.11n technologies. A further doubling of the data rate in 802.11ac is achieved by increasing the maximum number of spatial streams to eight.
IEEE 802.11ac further supports multiple concurrent downlink transmissions (“multi-user multiple-input, multiple-output” (MU-MIMO)), which allows transmission to multiple spatial streams to multiple clients simultaneously. By using smart antenna technology, MU-MIMO enables more efficient spectrum use, higher system capacity and reduced latency by supporting up to four simultaneous user transmissions. This is particularly useful for devices with a limited number of antennas or antenna space, such as smartphones, tablets, small wireless devices, and the like. 802.11ac streamlines the existing transmit beamforming mechanisms which significantly improves coverage, reliability and data rate performance.
IEEE 802.11ax is the successor to 802.11ac and is proposed to increase the efficiency of WLAN networks, especially in high density areas like public hotspots and other dense traffic areas. 802.11ax will also use orthogonal frequency-division multiple access (OFDMA). Related to 802.11ax, the High Efficiency WLAN Study Group (HEW SG) within the IEEE 802.11 working group is considering improvements to spectrum efficiency to enhance system throughput per area in high density scenarios of APs (Access Points) and/or STAs (Stations).
In current wireless broadband communications standards and systems development, transmission power control protocols have played a key role for interference mitigation and system performance improvement. These interference mitigation and system perform improvements have been designed and included as an essential part of the key wireless communications standards, such as 3GPP LTE, IEEE 802.16, and the like.
However, many cost sensitive wireless broadband communications systems, such as Wi-Fi and 802.11, have the following requirements:
1) A low cost power amplifier is strongly preferred. However, with low cost power amplifiers, power adjustment may not be able to be accurately controlled.
2) Due to the low cost of the system, pathloss measurement errors in Wi-Fi may reach 5 to 10dB—which may greatly degrade the performance of the conventional power control algorithms' gain.
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the disclosed techniques. However, it will be understood by those skilled in the art that the present embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the present disclosure.
Although embodiments are not limited in this regard, discussions utilizing terms such as, for example, “processing,” “computing,” “calculating,” “determining,” “establishing”, “analyzing”, “checking”, or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, a communication system or subsystem, or other electronic computing device, that manipulate and/or transform data represented as physical (e.g., electronic) quantities within the computer's registers and/or memories into other data similarly represented as physical quantities within the computer's registers and/or memories or other information storage medium that may store instructions to perform operations and/or processes.
Although embodiments are not limited in this regard, the terms “plurality” and “a plurality” as used herein may include, for example, “multiple” or “two or more”. The terms “plurality” or “a plurality” may be used throughout the specification to describe two or more components, devices, elements, units, parameters, circuits, or the like. For example, “a plurality of stations” may include two or more stations.
Before undertaking the description of embodiments below, it may be advantageous to set forth definitions of certain words and phrases used throughout this document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, interconnected with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, circuitry, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this document and those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.